THIS IS NOT A BUG IN AKELPAD! But... I have seen this problem in many other applications...

This is (I believe) a known problem with the listview control when used with ComCtl32.dll and LVS_EX_GRIDLINES. I'm not sure, but I also believe it may have something to do with the sizing of the listview control - if the size is EXACTLY right (on line boundaries, to the pixel) then the problem is not present. The Scripts and Macros plugin (list scripts and macros), for example, do NOT suffer from this problem - but the sizing appears EXACTLY right!

Behavior: dragging the slider up/down is fine - lines are repainted properly, but using the up/down arrows of the slider, or clicking above/below (pageup/pagedown) fails to repaint the control properly and the lines are "jumbled".

Question: Can this be fixed by a repaint after each scroll? Or can the control just be resized as a "fix"?

Any operation that causes the window to be repainted (eg. shift focus to another window, then back again) makes the window draw OK. I have read in forums (and on MSDN) about problems with having different versions of ComCtl32.dll on your system - changing to all the same version does not make this go away on my system (XP Pro, SP2).